1. Field of the Invention
The present invention relates to a refrigerating and air-conditioning system, and more particular, to a refrigerating and air-conditioning system, in which a refrigerating apparatus and an air-conditioning apparatus, respectively, have independent circulation flow passages.
2. Related Art
In order to improve the energy saving quality of a refrigerating apparatus, which comprises showcases installed in a store and so on for refrigeration and cold storage, and a refrigerating machine, it has been proposed to connect the showcases and the refrigerating machine together via communication lines to control an operating set pressure of a compressor, which is provided in the refrigerating apparatus, in view of a situation such as a load on the showcases, that is, a refrigeration or cold storage load on the showcases to vary an operating frequency of the compressor for capacity control (for example, JP-A-8-271063, pages 4 to 6, FIG. 2).
Meanwhile, an air-conditioning apparatus is mounted in a store or the like together with a refrigerating apparatus. Therefore, there has been proposed a refrigerating and air-conditioning system, in which a refrigerating apparatus and an air-conditioning apparatus, respectively, having independent circulation flow passages are combined together and when the air-conditioning apparatus runs in heating operation, exhaust heat from the refrigerating apparatus is recovered to condense a refrigerant in the air-conditioning apparatus for an improvement in energy saving quality. In such refrigerating and air-conditioning system, a refrigerating machine is provided with a heat recovery mechanism, which includes a heat exchanger capable of conducting heat to a heat exchanger provided in an outdoor equipment of the air-conditioning apparatus, and there is provided a control unit connected electrically to a control unit of the refrigerating apparatus and a control unit of the air-conditioning apparatus to actuate the heat recovery mechanism of the refrigerating apparatus when the air-conditioning apparatus runs in heating operation (for example, JP-A-2001-289532, pages 5 to 10, FIGS. 1 and 16).
Conventional refrigerating apparatus automatically reduces a set pressure (suction pressure) of a compressor for a refrigerating machine trying to follow an increase in a load on showcases, when showcases are increased in load to become high in operating efficiency. Therefore, a refrigerant is reduced in evaporating temperature, and the refrigerating machine is in some cases reduced in operating efficiency to be increased in power consumption. It has been desired that the energy saving quality be improved by suppressing an increase in power consumption, which is resulted from reduction in operating efficiency of the refrigerating machine.
Meanwhile, conventional refrigerating and air-conditioning systems are reduced in energy consumption when an air-conditioning apparatus runs in heating operation, but no consideration is taken of that reduction in energy consumption on a refrigerating apparatus side, which is caused by combining a refrigerating apparatus and an air-conditioning apparatus, respectively, having independent circulation flow passages together to form a refrigerating and air-conditioning system. Therefore, a refrigerating and air-conditioning system is desired, which can be improved in energy saving quality by combining a refrigerating apparatus and an air-conditioning apparatus, respectively, having independent circulation flow passages together to form a refrigerating and air-conditioning system.